Backyard Aquaponics
A place to discuss aquaponics

I've got a bit of a problem with a grub that's eating my tomato's.
from the outside it makes a pin hole, and ejects some brownish/black crud. when you cut into this you find a single grub behind each hole.
nothing seems to keep it at bay (that's fish safe) and i've lost a fair bit of crop. the only solution i can see is to bag my tomatoes?

Have you tried Dipel ??

yep doesn't work, i think it's because the grub lives inside the tomato.

Doesn;t sound nice... Sounds like they would be hard to control even if you could spray something on it.

Dipel works for me and should for any grubs I would have thought. My main problem and the moment is birds eating ripening fruit. Gotta sack that cat

With dipel they have to actually eat it, great if you have leaf eating bugs. But if you have a bug that lays eggs inside inside the fruit and they hatch out in the fruit and eat it inside, they will never actually get to eat any dipel thats on the outside..

ahh yes , very true. I dont think we have any insects that lay eggs in fruit so thats why Dipel works for me

I always used tomato dust in my soil gardening... but I'd be suspect whether it was fish safe... effective though... I'll read up...

http://www.dpi.nsw.gov.au/aboutus/servi ... pillar.jpg
It looks like the eggs are laid on the flower so that would be the place to spray as well as the baby tomatoes before they enter.
I would companion plant marigold basil or both to confuse them maybe even cat mint.
Let carrots or coriander go to seed to provide habitat for predatory wasps

Could well be the heliothis moth!! Rotten thing that it is. I would remove any signs of infested leaves and green fruit that have holes in them. Destroy damaged foliage and fruit, spray with dipel for future flowers and fruit and keep it up weekly, reapply if rain occurs. Set beer traps to get any slugs and remove any foliage below the fruit to reduce the opportunity for caterpillars to hide. Goodness then goes in to fruit and new growth, make sure the bed is clean and keep looking, the best protection that you can give your plants is your shadow! Hope this helps
Feed any slow caterpillars to the fish, this turns them in to a feast fit for the dinner plate, Yummy!

I think your right faye.
I'm going to net my entire grow bed, it's the only solution that'll work as i'm away from home a week or more at a time and i'm unable to keep up the spraying/picking.

I'm going to have to do the same for my fruit tree's as well as fruit fly hit me hard this year

Do you have an ID for grubs? Knowing what they are may make it easier to figure out how to keep the adults at bay.

Have you ever tried BT? Keeps them off for several weeks. You wont be able to get the grubs that are already inside tomatoes but it will prevent future attacks. Like Faye said just remove the already infected fruit.

faye is right, it's heliothis moth.
BT doesn't work on them, I tried copious amounts of it. removing the infected fruit just means i end up removing 90% of my crop.
even in my dirt garden stronger sprays didn't stop it so it's not just an AP problem.

netting the entire plant is my only option i think.

I found after eating the leaves sprayed with Dipel (BT) that I was able to get the slow moving caterpillars and find them in the day time, previously they had hidden. I still feed them to the fish as well. They will hide down in the media, so the other thing that I did was to flood the bed and collect them for the fish. The idea of removing the fruit (and grub) it can help to break the breeding cycle. Prevention and hygiene, treatment as well as manual removal. I also had to keep up a prolonged approach, this meant daily surveillance and repeat spraying.